COVID19 SARS Vaccinations: Systemic Allergic Reactions to SARS-CoV-2 Vaccinations
Public ClinicalTrials.gov record NCT04761822. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Systemic Allergic Reactions to SARS-CoV-2 Vaccination
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Background: Allergic reactions have been reported to occur after vaccination with both the Pfizer-BioNTech COVID-19 Vaccine and Moderna COVID-19 Vaccine. Allergic reactions range from mild to severe and include life- threatening anaphylactic reactions, although no deaths have been reported with either vaccine. This study is designed with two principal aims: * To estimate the proportions of systemic allergic reactions to the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 Vaccine in a High-Allergy/Mast Cell Disorder (HA/MCD) population, and * If the risk in the HA/MCD is demonstrable, to determine whether the proportions are higher in the HA/MCD in comparison to a representative population without severe allergies or mast cell disorders
Study identification
- NCT ID
- NCT04761822
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 746 participants
Conditions and interventions
Interventions
- Moderna COVID-19 Vaccine Biological
- Pfizer-BioNTech COVID-19 Vaccine Biological
- Placebo Biological
Biological
Eligibility (public fields only)
- Age range
- 5 Years and older
- Sex
- All
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Apr 7, 2021 (Actual)
- Primary completion
- Apr 20, 2022 (Actual)
- Completion
- Apr 27, 2022 (Actual)
- Last update posted
- Aug 12, 2025
2021 – 2022
United States locations
- U.S. sites
- 29
- U.S. states
- 20
- U.S. cities
- 27
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| University of Arizona Health Sciences, College of Medicine Tucson, Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine | Tucson | Arizona | 85724 | — |
| Arkansas Children's, University of Arkansas for Medical Sciences | Little Rock | Arkansas | 72202 | — |
| University of California, Los Angeles Medical Center | Los Angeles | California | 90095 | — |
| Stanford Medicine, Sean N. Parker Center for Allergy & Asthma Research | Stanford | California | 94040 | — |
| National Jewish Health | Denver | Colorado | 80206 | — |
| University Health, University of Miami Health System | Miami | Florida | 33136 | — |
| University of South Florida Asthma Allergy and Immunology Clinical Research Unit | Tampa | Florida | 33613 | — |
| Emory University School of Medicine, Emory Healthcare: Emory Clinic Allergy and Immunology | Atlanta | Georgia | 30324 | — |
| Sinus and Allergy Center of Northwestern University | Chicago | Illinois | 60611 | — |
| NorthShore University HealthSystem, Dermatology Clinical Trials Unit | Skokie | Illinois | 60077 | — |
| University of Iowa Health Care | Iowa City | Iowa | 52242 | — |
| Johns Hopkins Bayview Medical Center | Baltimore | Maryland | 21224 | — |
| Massachusetts General Hospital | Boston | Massachusetts | 02114 | — |
| Brigham and Women's Hospital | Boston | Massachusetts | 02115 | — |
| University of Michigan Health | Ann Arbor | Michigan | 48109 | — |
| Henry Ford Hospital and Health System | Detroit | Michigan | 48202 | — |
| Saint Louis University Care Center for Specialized Medicine | St Louis | Missouri | 63104 | — |
| Mount Sinai Hospital, Department of Medicine, Division of Clinical Immunology | New York | New York | 10029 | — |
| Columbia University Irving Medical Center | New York | New York | 10032 | — |
| Rochester Regional Health | Rochester | New York | 14607 | — |
| North Carolina Translational and Clinical Sciences Institute-Clinical & Translational Research Center (CTRC) at the University of North Carolina at Chapel Hill | Chapel Hill | North Carolina | 27599 | — |
| Cleveland Clinic, Allergy & Clinical Immunology | Cleveland | Ohio | 44195 | — |
| Penn State Health Allergy, Milton S. Hershey Medical Center | Hershey | Pennsylvania | 17033 | — |
| Vanderbilt University Medical Center | Nashville | Tennessee | 37232 | — |
| University of Texas Southwestern Medical Center | Dallas | Texas | 75390 | — |
| Baylor College of Medicine Medical Center | Houston | Texas | 77030 | — |
| University of Virginia Health System: Department of Medicine, Division of Allergy and Immunology | Charlottesville | Virginia | 22908 | — |
| Virginia Commonwealth University, Department of Internal Medicine, Division of Rheumatology, Allergy & Immunology | Richmond | Virginia | 23298 | — |
| University of Wisconsin Asthma Allergy Pulmonary Research | Madison | Wisconsin | 53792 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04761822, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Aug 12, 2025 · Synced Oct 24, 2026
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Open the official record
The complete public registry record, listed eligibility criteria, and available contact information for NCT04761822 live on ClinicalTrials.gov.